Movable support for a dental chair



Dec. 30, 1969 NAUGHTON I 3,486,728

MovAB'LE lSUPPORT FOR A DENTAL CHAIR vFiled May 5, 1967` United States Patent O U.S. Cl. 248-429 3 Claims ABSTRACT F THE DISCLOSURE A carriage plate for mounting the base of a dental chair is movably supported for guided movement longitudinally of a iloor plate by means including an upright longitudinally extended track on the floor plate. Located between the carriage and the oor plate and carried from the under side of the carriage is a clamping mechanism that includes a pair of pivoted lever members arranged at opposite sides of the track. To releasably lock the carriage, and in turn the dental chair, against movement relative to the iloor plate, the lever members are concurrently movable into and out of locking engagement with transversely opposite side surfaces of the track by a cornmon operating member disposed beneath the carriage and actuated by a foot member located above the carriage.

SUMMARY OF THE INVENTION The movable support for the dental chair is of a llat construction so that the chair in its lowermost adjusted position is at a convenient level providing for a free and comfortable working movement of the dentist relative to the patient when the dentist is in a sitting position. The head of a patient, during adjustment of the dental chair between upright and reclining positions therefor, is moved relative to a usual console that carries the dental instruments, mouth -rinsing devices and the like. The movable support provides for the chair being readily moved relative to the console so that both the patient and the instruments are always at the fingertips of the dentist.

The mechanism for locking the chair in a moved position is completely covered by and supported on a movable carriage plate with only a foot actuating pedal being exposed for convenient manipulation. A pair of clamping members, that form a part of the locking mechanism, are arranged to engage transversely opposite sides of a guide track that is provided on a oor support lfor the carriage plate.

The locking mechanism operates smoothly and quietly to retard the travel of the chair into moved position and to positively lock the chair in such position without inju-ry or damage to any of the coacting bearing surfaces of the mechanism.

DETAILED DESCRIPTION OF THE INVENTION Further objects and features of the invention will become apparent from the following detailed description when taken in consideration with the accompanying drawings in which:

FIG. l is a perspective view of the movable support of this invention, with parts broken away to more clearly show its construction;

FIG. 2 is an enlarged sectional detail view taken on the line 2 2 in FIG. 1 and showing the chair locking mechanism;

FIG. 3 is an exploded perspective view of the locking mechanism;

FIG. 4 is an enlarged top plan view taken substantially along line 44 in FIG. 2 showing the locking mechanism in locking position with a cam operator member being illustrated in phantom for the purpose of clarity;

FIG. 5 is a plan view illustrated similarly to FIG. 4

Patented Dec. 30, 1969 showing the locking mechanism in a -releasing or unlocking position; and

FIG. 6 is a perspective view of a dental chair in assembly relation with the movable support of this invention.

Referring to the drawing, the movable support of this invention, indicated generally at 10 in FIGS. 1 and 6, is shown in FIG. 6 in assembly relation with a dental chair 11 having a base 12, a seat section 13 and a back section 14 that is adjustable relative to the seat section 13. The base 12 is mounted directly on a carriage plate 16 which forms part of the movable support 10.

The chair 11 (FIG. 6) is shown with the back rest section 14 in an upright position and arranged relative to an instrument console, indicated at 17, such that with the dentist in a standing position the instruments are conveniently accessible for working on a patient. If the back rest is lowered to provide for the dentist working from a seated position, it is seen that the patients head would be moved rearwardly relative to the console so as to locate the instruments out of convenient reach for use. However, by moving the chair forwardly on the support 10 accessibility to the patient in the chair and to the inst-ruments on the console is maintained.

The suport 10 (FIG. 1) includes a floor plate 18 having a body section 19 of a rectangular shape provided with a rearward longitudinal extension 21. An upstanding track 22 extends centrally and longitudinally of the iloor plate 18 over the combined lengths of the body section 19 and the extension 21. The carriage plate 16 is positioned on the Hoor plate 18 and is of a generally square shape and of a size to cover the body section 19. Rotatably carried on the underside of the carriage plate and at each corner thereof is a roller 23, with the rollers 23 at the front corners :being ridable on the floor plate 18. The rollers 23 at the rear corners of the carriage plate 16 function essentially as outriggers to maintain the carriage plate 16 substantially level when it is moved to a position over the extension 21. In other words, the rear corner rollers 23 are normally in a clearance relation with the floor surface but are engageable with the floor to limit the sidewise tilting movement of the carriage plate 16 when it is over the extension 21.

Also mounted on the underside of the carriage plate 16 are a pair of front rollers 24 and two pairs of rear rollers 25 and 26. The rear rollers 26 are ridable on the iloor plate 18 and arranged to opposite sides of a lock mechanism 28 (FIG. 2) for holding the carriage plate 16, and in turn the chair 11, against movement relative to the floor plate 18. The front rollers 24 and rear rollers 2S are in contact or guiding engagement `with corresponding opposite sides 27 of the track member 22.

The locking mechanism 28 (FIGS. 3 and 4) is disposed beneath the carriage plate 16 and includes a pair of pivoted levers 29 and 31 extended longitudinally at opposite sides of the track 22. Each lever is bent intermediate its end to form laterally oilset front and rear sections 32 and 33, respectively, with the rear sections 33 lying in a horizontal plane below the plane of the front sections 32 as best appears in FIG. 3. The forward end of each front section 32 is pivotally connected at 34 to the underside of the carriage plate 16 for pivotal movement of the levers 29 and 31 about vertical axes. Each rear section 33, at the free end of a lever 29 and 31, is formed with a clamping jaw 36 that extends laterally toward an adjacent side 27 of the track 22.

On pivotal movement of the levers 29 and 31 in relative reversed directions the clamping jaws 36 are moved into and out of frictional clamping engagement with corresponding sides 27 of the track 22. As lbest appears in FIG. 2 of the surfaces of the track sides 27 and the engaging surfaces 37 of the clamping jaws 36 lie in vertical planes. Also when the levers 29 and 31 are in locking positions the jaw surfaces 37 are in a parallel relation with the side surface of the track 22 (FIG. 4) Thus, the entire area of a jaw surface 37 is in frictional engagement with an adjacent track side surface when the levers 29 and 31 are in locking position.

A relative reversed pivotal movement of the levers 29 and 31 to locking and unlocking positions therefore is accomplished by means including an interconnected operating or cam plate members 39 (FIGS. 4 and 5). The cam plate is of a disc shape and is positioned above the rear sections 33 of the levers 29 and 31 so as to lie in substantially the plane of the front sections 32. An upright stub shaft 41 on the cam plate 39 is projected through and rotatably supported in a bearing sleeve 42 that is mounted on the carriage plate 16. An actuating lever 43 has a hub portion 44 positioned on the projected end of the shaft 41 and secured thereto by a pin 46 which is extended radially through aligned holes in the hub 44 and shaft 41. One or more washer bearings 47 (two are illustrated) are mounted, as required, on the shaft 41 between the hub 44 and the sleeve bearing 42 to support the cam plate 39 against the underside of the carriage plate 16.

The cam plate 39 is formed with a pair of diametrically opposite arcuate slots 48 and 49 corresponding, respectively, to the levers 29 and 31. The free end of each lever 29 and 31 has an upright roller 51 receivable in a following relation within a corresponding slot 48 and 49. The slots are eccentrically arranged relative to the axis of rotation of the shaft 41 or cam plate 39 so that on oscillation of the cam plate 39 the clamping jaws 36 are moved into and out of clamping engagement with the track 22.

Thus, as shown in FIGS. 4 and 5, the axis of rotation of the cam plate 39 is indicated at A; and the centers or radii of generation for the slots 48 and 49 are indicated at B and C, respectively, at positions offset to opposite sides of the axis A. When the levers 29 and 31 are in locking position the rollers 51 are at their innermost positions relative to the axis of rotation A (FIG. 4). As the levers 29 and 31 are moved out of locking position, the rollers 51 are progressively moved farther away from the axis A (FIG. relative totheir positions shown in FIG. 4. As illustrated for the position of the actuating lever 43 in FIGS. 4 and 5, the levers 29 and 31 are movable into and out of locking position, relative to the track 22, in response to only about a ninety degree roation of the cam plate member 39.

It is also seen that when the levers 29 and 31 are out of locking engagement with the track 22, the surfaces 37 of the jaws 36 are in close proximity to the track 22, but freely movable relative to the track. Thus, during movement of the dental chair 11 the front pair of rollers 24 and the rear rollers 25 function to provide for a guided movement of the chair 11 longitudinally of the oor plate 18. This longitudinal movement of the chair in a forward direction is limited by the abutting engagement of an upstanding pin 52 (FIG. l) on the oor plate 18 with a rear pin 53 depended from the underside of the carriage plate 16. Rearward movement of the chair 11 is limited by the engagement of the pin 52 with a front depending pin 54 on the carriage plate, it being understood that the pins 52, S3 and 54 are in linear alignment.

When the chair is being moved to an adjusted position, it may be initially arrested and then locked by a continuous pivotal movement of the actuating lever 43. By virtue of the full bearing engagement of the surfaces 37 on the clamping jaws 36 with the side surfaces 27 of the track 22 such arresting and locking action takes place smoothly and positively and without damage to either the bearing surfaces 37 or track side surfaces 27.

It is further seen that the locking mechanism 28 is or a simple and compact construction and except for the actuating lever 43 is disposed entirely to the underside of the cover plate 16 which functions to shield or cover the locking mechanism 28 and all of the roller supports for the carriage plate. By virtue of the longitudinal extension 21 on the body section 19 of the oor plate 18, a free and unobstructed oor surface is provided for the dentist in Working on a patient when the carriage plate 16 is over the oor plate 18 corresponding to the maximum moved forward position of the chair 11.

Although the invention has been described with respect to a preferred embodiment thereof, it is to be understood that it is not to be so limited since changes and modifications can be made therein which are within the full intended scope of this invention as defined by the appended claims.

I claim:

1. A support for a dental chair having a base member comprising:

(a) a carriage plate for supporting the base member thereon,

(b) a oor plate having an upstanding longitudinal rail with vertically extended side surfaces,

(c) a plurality of rollers on the underside of said carriage plate supporting the carriage plate for movement on and longitudinally of the oor plate in a guided relation with said rail,

(d) a pair of lever members each having a clamping jaw at one of the ends thereof, each clamping jaw having a vertically extended contact surface,

(e) means pivotally connecting the lever members at the other ends thereof to the underside of the carriage plate for pivotal movement of said clamping jaws into and out of engagement with transversely opposite portions of said side surfaces, said contact surfaces, when the clamping jaws are out of engagement with said side surfaces being spaced from and inclined longitudinally of corresponding ones of side surfaces and, when the clamping jaws are in engagement with said side surfaces, being coplanar with and in bearing engagment with corresponding ones of said side surfaces,

(f) a cam assembly rotatably supported on said carage plate including an actuating member located above said carriage plate and a lever operating cam plate disposed beneath said carriage plate, and

(g) means connecting said cam plate with said pair of levers whereby in response to pivotal movement of said actuating member said clamping jaws are movable into and out of engagement with the transversely opposite portions of said side surfaces,

(h) a foot actuated member connected to said shaft means for pivotally moving the cam means to said locking and unlocking positions therefor.

2. A support for a dental chair according to claim 1 wherein:

(a) said cam assembly is rotatably supported for rotation about a vertical axis which is extended through the rail and between said clamping jaws.

3. The support for a dental chair according to claim 2,

wherein:

(a) said connecting means includes an upright projection at the opposite end of each lever, and (b) said cam plate having a pair of arcuate slots corresponding to and receiving said upright projections therein.

References Cited UNITED STATES PATENTS 55,343 6/1866 Murray 24-263.4 188,056 3/1877 Johnson 188-43 370,388 9/1887 Goddu 18S-43 2,540,888 2/1951 Hyatt. 3,259,355 7/1966 Slouka 24S- 430 FRANCIS K. ZUGEL, Primary Examiner U.S. Cl. X.R. 297-344 

